1. Field of the Invention
This invention relates to a connector of a wire harness of an automobile or the like and, more particularly, to a connector having an improved water-resistant structure.
2. Description of the Related Art
A connector having a housing adapted to receive a terminal fixture of a wire harness of an automobile or the like is known. A terminal cavity for the reception of the terminal fixture is formed in the connector housing with the two ends of the terminal cavity constituting an insertion-side opening through which a terminal fixture is inserted and a connection-side opening through which a mating connector is inserted. That is, the terminal fixture is inserted through the insertion-side opening with the tip thereof facing the connection-side opening. Afterwards, the terminal fixture within this terminal cavity and the terminal fixture of the mating connector are connected via the connection-side opening.
Water-resistance measures in such a connector include a rubber seal fitted to the junction of the terminal fixture and the lead wires electrically connected thereto. The rubber seal forms a watertight seal at the insertion-side opening when the terminal fixture is inserted into the terminal cavity thereby preventing the penetration of water from the insertion-side opening to within the terminal cavity.
However, because such a connector is a general-use part for forming various electrical circuits, i.e. is configured depending on the circuit in which it is employed, terminal fixtures may not be inserted into all of the terminal cavities. That is, some of the terminal cavities may be left vacant. A dummy plug made of rubber and having an outer diameter similar to that of the rubber seal is commonly inserted as a water-resistant measure for such vacant cavities. Of course, whether a vacant terminal cavity like that described above will be left in the connector can be ascertained in the circuit design stage. Therefore, it is possible to forego this route and instead manufacture specialized connector housings of different specifications by means of differing molds so that excess terminal cavities to be left vacant are not formed. However, such a change in specifications involves a change in the basic structure of the mold. This creates an increase in cost because a completely different mold must be manufactured. This increase in cost is rather prohibitive. For reasons such as this, the combination of a general-use connector with dummy plugs has become commonplace in the prior art.
However, the following problems are associated with this connector.
First, the installation of the dummy plug is performed manually. Therefore, not only does the possibility exist that the dummy plug is not installed because of operator error or the like, but there is a chance that even if the dummy plug is installed it may not be installed securely and may fall out of the cavity. Thus, the prior art connector cannot be relied upon for its water resistance.
Additionally, because a dummy plug is a discrete specialized part for providing water resistance, there is the drawback of the cost associated with each dummy plug.
Furthermore, because the terminal cavity in which a terminal fixture is to be inserted and the terminal cavity in which a terminal fixture is not to be inserted have identical configurations when viewed from the insertion-side opening, there is a chance that a terminal fixture may mistakenly be inserted into a terminal cavity in which it should not have been inserted in terms of the make-up of the electric circuit to be formed.